﻿using Code_Graph.Project.Datas;
using System;
using System.Collections.Generic;
using System.Windows.Input;
using System.Xml.Linq;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.ApplicationModel.Resources;
using Windows.Storage.Streams;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;
using System.IO;
using System.Linq;

namespace Code_Graph
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    sealed partial class App : Application
    {
        //@Strings
        internal static readonly ResourceLoader Resource = ResourceLoader.GetForCurrentView();

        /// <summary>
        /// Initializes the singleton application object.  This is the first line of authored code
        /// executed, and as such is the logical equivalent of main() or WinMain().
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;
        }

        protected override async void OnFileActivated(FileActivatedEventArgs args)
        {
            foreach (IStorageItem item in args.Files)
            {
                if (item is IStorageFile file)
                {
                    using (IRandomAccessStream stream = await file.OpenAsync(FileAccessMode.Read))
                    {
                        XDocument document = XDocument.Load(stream.AsStream());
                        IEnumerable<GroupData> datas = MainPage.Load(document);
                        if (datas.Count() == 0) break;

                        Frame rootFrame = Window.Current.Content as Frame;

                        if (rootFrame.Content is MainPage page)
                        {
                            ICommand command = page;
                            command.Execute(datas.ToArray()); // Command
                        }
                        else if (rootFrame.Content == null)
                        {
                            rootFrame.Navigate(typeof(MainPage), datas.ToArray());
                            Window.Current.Activate();
                        }
                    }
                }
            }
        }

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used when the application is launched to open a specific file, to display
        /// search results, and so forth.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
            Frame rootFrame = Window.Current.Content as Frame;

            // Do not repeat app initialization when the Window already has content,
            // just ensure that the window is active
            if (rootFrame == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page
                rootFrame = new Frame();

                rootFrame.NavigationFailed += OnNavigationFailed;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    // Load state from previously suspended application
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;
            }

            if (e.PrelaunchActivated == false)
            {
                if (rootFrame.Content == null)
                {
                    // When the navigation stack isn't restored navigate to the first page,
                    // configuring the new page by passing required information as a navigation
                    // parameter
                    rootFrame.Navigate(typeof(MainPage), e.Arguments);
                }
                // Ensure the current window is active
                Window.Current.Activate();
            }
        }

        /// <summary>
        /// Invoked when Navigation to a certain page fails
        /// </summary>
        /// <param name="sender">The Frame which failed navigation</param>
        /// <param name="e">Details about the navigation failure</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// Invoked when application execution is being suspended.  Application state is saved
        /// without knowing whether the application will be terminated or resumed with the contents
        /// of memory still intact.
        /// </summary>
        /// <param name="sender">The source of the suspend request.</param>
        /// <param name="e">Details about the suspend request.</param>
        private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();

            deferral.Complete();
        }
    }
}
